More than 20 people have died after a suicide bomber blew himself up at a lunch hosted by a Sunni candidate in Iraq's upcoming regional elections, officials said.

Suicide bomber kills more than 20 in Iraq. Credit: Reuters

A police officer said Muthana al-Jourani, who is running for the provincial council and held the lunch rally for supporters, was injured in the attack, and had not requested any extra security for the political event.

The blast ripped through a hospitality tent pitched next to the house of al-Jourani, councilman Sadiq al-Huseini said.

The attack took place in Baquba, a mixed Sunni-Shiite city some 35 miles (65 km) north east of Baghdad.